As such a type of conventional directional control valve device, there is a device disclosed in Patent Literature 1 (Japanese Examined Utility Model Publication No. 4-38144) below.
In the above conventional art, two-way directional control valves of the same type are arranged in parallel, thereby constituting the directional control valve device. The switching positions of operating levers provided to the directional control valves, respectively, are caused to affect each other by a mechanical interlock device.